Goals of the proposed project are to understand how prestriate cortex transforms afferent visual information, and to investigate the function of the projection of the pulvinar to prestriate cortex. Responses of cells in Area 18 will be studied in the awake, behaving monkey, and quantitative measures of sensitivity to orientation, direction and luminance obtained. Tecto-pulvinar-prestriate system will be analyzed first by studying effects of pulvinar-prestriate system will be analyzed first by studying effects of pulvinar lesions on eye movements and, second, by comparing Area 18 prestriate response properties in normal and pulvinar-lesioned animals.